Sean advises clients, including early-stage startups, unicorns, and Fortune 100 multinationals on a wide array of domestic and international tax planning and tax controversy matters.

Sean has particular expertise advising clients on tax matters related to blockchain and cryptocurrency ecosystems. He has advised numerous clients on tax issues relating to token generation events, private token sales, NFTs, DAOs, and centralized and decentralized cryptocurrency structures. Sean’s clients in this space include protocol development teams, founders, investment platforms, cryptocurrency exchanges, and individual investors.

Sean also has experience representing clients in tax controversies. He has represented large multinational companies in advance pricing agreements, tax arbitrations, administrative proceedings against the IRS, in U.S. District Court, and in the U.S. Tax Court. Sean has also represented taxpayers in controversies relating to the taxation of cryptocurrency.

Sean is a lecturer in law at Stanford Law School, where he teaches a course in Blockchain Tax.